Royal College of Surgeons. It is a semi-diagrammatic rendering of the branchial arches and their relations to the roof and floor of the mouth in the Pike (Esox Lucius) as they are seen through the widely-opened jaws of the fish.

In the endeavour to make plain as much as possible which lies in a confined space, some violence has been done to perspective. Nevertheless, the drawing is fundamentally correct. In order that the figure may not be more obscure than it is feared it may possibly be already, the gill-plates and inwardly-directed fringes of teeth have been omitted.

G Tube of the gullet.
t Rudimentary tongue.
ps Parasphenoid bone.

The rest of the letters have the same signification as those in the preceding figure.

The dotted parts of the diagram indicate those regions of the threshold of the gullet which carry a rasp-like armature of small teeth.

FIG. 4. Taken from part of the right side of the specimen-a dried and varnished head of a Pike-on which the preceding diagram is based. The operculum and branchiostegal rays and membrane are here fairly shown.

o Operculum.

so Suboperculum. po Preoperculum.

io Interoperculum.

ch Ceratohyal, which joins anteriorly the median, tonguebearing basihyal.

eh Epihyal, which is joined on behind to the slender stylohyal, which, in its turn, articulates with the hyo-mandibular bone; all which relations are concealed by the overlapping operculum.

The cerato and epi-hyals are each seen to carry seven branchiostegal rays (b s), the former on its inner, the latter on its outer side.

m Lower part of mandible.

A flexible membrane, better

seen in Fig. 1, fills up the gap between it and the upper edge of

the cerato- and epi-hyals.

FIG. 5. After Cuvier (Hist. Nat. des Poissons, tome i. pl. viii. fig. 6), represents a transverse section of the gill-bearing elements of a branchial arch of a Perch, together with its attached gill-plate ("feuillet," Cuv., or "branchial lamina"), which is seen to be made up of two leaflets.

br Bone of the arch in section.

b a Branchial artery in section. It may be observed to divide into two branches, one for each gill-plate, each of which courses along the inner edge of a leaflet, giving off in its course numerous slender twigs. The purified blood is returned to the branchial vein—which is seen in section at b v-by two trunks which run each along the outer edges of the two leaflets which are the components of a gill-plate, having been first collected in small vessels which meet the arterial twigs on the mutual terri

tory of the capillary system. The carrier of the purer blood is seen to occupy a deeper and, presumably, a safer position than does its fellow, at the bottom of the groove which is channelled out along the convex edge of its bony support.

The arrows indicate the course of the blood.

FIG. 6. Head of a species of Pipe-fish (Syngnathus Æquoreus) from a preparation (No. 1041) in the Museum of the Royal College of Surgeons.

The operculum on the right side has been removed, in order to display the gills, which are "composed of a double series of tufts on each of the four arches."

ba Bulbus arteriosus-the root, so to speak, of the trunk which gives off an arterial branch for the gills of either side. FIG. 7. Head of another specimen of the Pipe-fish (Syngnathus Sp:?) captured by the author in an oyster-dredge off Seaview, Isle of Wight.

op Operculum, left side. Above and behind it is seen the small outlet (*), just large enough to admit a bristle, for the water which has bathed the gill-tufts.

FIG. 8. The pharynx of the same specimen opened out in order to show the five fissures on either side which admit water to the tufted

gills.

FIG. 9. Much reduced from a sketch of a preparation (No. 1060) in the Museum of the Royal College of Surgeons, of the head of the Gray Shark (Galeus communis). The right half of the head, through which a vertical longitudinal section has been made, is preserved in the preparation. In the pharynx five openings are seen, which, guarded by tooth-like projections, not bony as in osseous fishes, but more or less cartilaginous, allow of the influx of water, which, after bathing the gills paired in their chambers, finds exit by five fissures at the side of the head.

œ œsophagus, or gullet.

sp opening leading to the canal which terminates externally at the so-called " spiracle" (Spritzloch").*

The arrows indicate the direction of the water swallowed for

respiration.

FIG. 10 is a diagram (Schema) after Gegenbaur (Grundzüge der Vergleichenden Anatomie, 2nd edit. fig. 210) of the cartilaginous skull and "visceral" skeleton of one of the Sclachii, e.g. Sharks and Rays.

o orbit, for lodgment of the eye.

I. II. First and second visceral arches, the former of which forms the boundary of the mouth, while the latter (“ hyoid”) carries the tongue.

III. VIII. Branchial arches, comprising the rest of the visceral skeleton.

The remnant of the first "visceral cleft," which in the bony fishes becomes closed up, but in ourselves is partly persistent as the external canal of the ear, and the Eustachian tube.

In Heptanchus there are nine or ten visceral arches.

FIG. 11. Taken from a preparation (No. 1018) in the Museum of the Royal College of Surgeons, represents two of the six gill-sacs on one side of the Myxine or "Glutinous Hag" (Heptatrema cirratum). These sacs, br b r, the upper of which is represented in profile, are seen internally to communicate with the œsophagus (œ), each by a short tube. Externally, they are brought into relation, by similar means, with one of the two longitudinal canals (not shown in the figure) which discharge the de-oxygenated water by two pores opening on the ventral surface of the body. The lowest arrows show the direction of the water used for respiration, which is admitted not at the mouth, as in other fishes, but at a small opening placed betwixt the two pores which allow of its exit. Each sac is further seen to be supplied with a branch from the branchial artery (a) of its side.

FIG. 12 is a view, from above, of the respiratory apparatus of the African Mud-fish, Lepidosiren (Protopterus) Annectens, reduced from a figure in Professor Owen's paper on the anatomy of this fish. (See Trans. Linn. Soc. vol. xviii. tab. 26, fig. 1).

The pharynx has been slit up in the middle line, and its sides spread out on either side.

The five branchial fissures are indicated by numbers.

t Tongue.

g Aperture, or glottis, pierced in the rudimentary thyroid cartilage (th) leading to the short " ductus pneumaticus," or trachea (dp), which, in turn, communicates with two lung-like sacs.

v is a valve which, though it is not stated to do so by Professor Owen, may act, to judge from the figure, as an epiglottis, i.e. prevent food, &c., from falling into the glottis.

[All figures founded by the author on specimens in the Museum of the Royal College of Surgeons were drawn by the kind permission of Professor Flower, F.R.S.]

* "The leading condition," says Professor Owen," of the gills in other fishes may be understood by supposing each compressed sac of a Myxine to be split through its plane, and each half to be glued by its outer smooth side to an intermediate septum, which would then support the opposite halves of two distinct sacs, and expose their vascular mucous surface to view. If the septum be attached by its entire margin, the condition of the plagiostomous gill is effected. If the septum be liberated at the outer part of its circumference, and the vascular surfaces are produced into pectinated lamelligerous processes, tufts, or filaments, proceeding from the free arch, the gill of an ordinary osseous or teleostomous fish is formed. Such a gill is the homologue, not of a single gill-sac, but of the contiguous halves of two distinct gill-sacs, in the Myxines. Already, in the Lampreys, the first stage of this bi-partition may be seen, and the next stage in the Sharks and Rays."

This throws much light upon the somewhat puzzling variations of the branchial arteries in fishes. See also Gegenbaur, op. cit. p. 809; and the Introduction of Professor Rolleston's Forms of Animal Life.

356

MR. CROOKES' NEW PSYCHIC FORCE.

BY J. P. EARWAKER, MERTON COLLEGE, OXFORD.

"SEFI

EEING is believing" is an old and much-quoted adage which is by many people so firmly believed in, that with them it quite partakes of the nature of a truism. To suggest for one moment the possibility of their being either partially or entirely mistaken, is to call in question their veracity, their powers of observation, and, in fact, their whole moral integrity, and is usually met, not by convincing arguments, but by indignant reiteration. To question the accuracy of their statements is considered in the light of a personal insult, and for anyone to cross-examine their narrations, however strange these may appear, is to them unbearable. But just as it is the firmest of all legal maxims, that no story can by any possibility be true which cannot stand the test of cross-examination, so it should be the test of all narrations, especially those of an extraordinary character, that they in their turn should stand the most rigid and searching cross-examination to which they can possibly be subjected.

Few ordinary readers of newspapers can have failed to notice how the first published accounts of any special or marked crime are so plausible, and apparently so convincing, that each reader feels there can be no doubt at all as to the guilt of the person accused. They have no means of knowing how far the plausible statements they read bring certain facts into undue prominence, and cast others equally important, but antagonistic, into the shade; but notwithstanding all this, they constitute themselves arbitrary judges on the first evidence that is thrust into their hands. When, however, the case is legally tried, and by cross-examination the evidence is thoroughly sifted, how different the case looks, what an innocent person the unfortunate accused is, what miseries he must have suffered, what imbeciles the police are, and so on, ad infinitum. The human mind is the same all the world over, at all times and in all ages-grossly credulous, most easily convinced,

quick to imagine, and equally quick to decide; and yet, when all its boasted judgment and foresight are proved utterly wrong, it is by no means taught by experience. At the next opportunity men commit the same errors of judgment, and again Experience would teach them; but all to no purpose; they cannot and will not be taught by her.

The history of popular delusions is one of the most instructive, and at the same time the most saddening of all historical narratives. The weakness of the so much lauded and boasted human understanding, the firm belief that men have placed, and apparently ever will place, in the mere statements of their fellow-men, the gross and almost unimaginable credulity they are constantly exhibiting, all these make up a picture as saddening as it is true. See how long and how widely the universal belief in astrology, magic, and witchcraft prevailed, and when these beliefs had to give way at the first dawn of true science, it was only to make place for new ones, until, in recent times, almost every ten years has seen a new imposture arise, has seen it in its full glory, and has witnessed its sudden overthrow. To mention but the titles of many of these would, to most of our readers, be but a string of mere names; but if we confine ourselves to the last fifty years only, what a rush of them there is-animal magnetism, the odic force, electrobiology, mesmerism, table-rapping, table-turning, spiritualism, &c. &c. The more apparently scientific the name, the more it was considered likely to take a hold on the public. But just as medical men find such great difficulty in convincing the great mass of mankind that thousands and thousands of lives are annually lost by a belief in quack medicines and quack doctors, so too now it has become most difficult for scientific men to make the outside world believe that the grossest impositions and the most outrageous impostures are constantly being palmed off upon them. Few people have any true idea how outrageous many of these pseudo-scientific delusions really are, and how they, like parasitic fungi, grow at the expense of those who support them.

The history of spiritualism illustrates this well. As far as we can remember, it first dawned upon the world from the other side of the Atlantic, under the shape of table-rapping and table-turning. An ordinary innocent table was stated to be capable of answering any questions put to it, and also of capering about and raising itself in the air, under the influence of some one or more persons whose innocent hands were placed lightly upon it. To account for the first series of these phenomena, some ingenious person called to his aid the spirits of departed persons; the ever-credulous world jumped at this theory, and its originators and followers, having thus struck a